1
|
Varying Synthesis Conditions and Comprehensive Characterization of Fluorine-Doped Hydroxyapatite Nanocrystals in a Simulated Body Fluid. CRYSTALS 2022. [DOI: 10.3390/cryst12020139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Bone supports animal bodies, is the place where blood is produced, and is essential for the immune system, among other important functions. The dominant inorganic component in bone is hydroxyapatite (Hap), the structure and dynamics of which still pose many unsolved puzzles. An updated understanding of HAp is of great significance to osteology, dentistry, and the development of artificial bone and other biomaterials. In this work, HAp nanoparticles were synthesized with the wet chemical precipitation method and their structure and morphologies were controlled by varying pH and adding fluoride ions by two different routes: (1) fluoride ions were added during synthesis, and (2) fluoride ions were introduced after the samples were synthesized by soaking the samples in solutions with fluoride ions. XRD and HRTEM were employed to confirm the composition and structure, while various multinuclear (1H, 19F, 31P) solid-state nuclear magnetic resonance (NMR) methods including 1D single pulse, cross-polarization under magic-angle spinning (CPMAS), and 2D heteronuclear correlation (HETCOR) were used to characterize the structure, morphology, and dynamics, validating the general core-shell morphology in these F-HAp samples. It was found that all hydroxide ions were substituted when the fluoride ion concentration was above 0.005 M. An NMR peak corresponding to water structure emerged and the bulk water peak was shifted upfield, indicating that fluoride substitution modifies both the crystalline core and the amorphous shell of F-HAp nanoparticles. With the second route of fluoride substitution, increases in soaking time or fluoride ion concentration could increase fluoride substitution in HAp, but could not achieve complete substitution. Finally, with 1H-31P CPMAS and HETCOR, it was established that there are two types of phosphorous, one in the crystalline core (PO43−) and the other in the amorphous shell (HPO42−). These results are valuable for clarifying the fluoride substitution mechanism in HAp in biomaterials or in organisms, and provide insights for developing next generation replacement materials for bone, tooth, or coating films, drug delivery systems, etc.
Collapse
|
2
|
Wang H, Falcoz S, Berteau JP. Long-Chain Fatty Acids in Bones and Their Link to Submicroscopic Vascularization Network: NMR Assignment and Relaxation Studies under Magic Angle Spinning Conditions in Intramuscular Bones of Atlantic Herring Fish. J Phys Chem B 2021; 125:4585-4595. [PMID: 33914538 DOI: 10.1021/acs.jpcb.1c00186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The long-lasting proton signals in bones are identified as long-chain fatty acids, including saturated, mono-, and di-unsaturated fatty acids, with direct nuclear magnetic resonance evidence. We used intramuscular bones from Atlantic Herring fish to avoid interference from lipid-rich marrows. The key is to recognize that these signals are from mobile phase materials and study them with J-coupled correlation spectroscopies under magic angle spinning conditions. We kept extensive 1H-spin-echo records that allowed us to examine the effect of magic angle spinning on the transverse relaxation time of water and lipids over time. While it is impossible to distinguish based on chemical shifts, the relaxation data suggest that the signals are more consistent with the interpretation of phospholipid membranes than triglycerides in lipid droplets. In particular, the simultaneous T2 changes in water and lipids suggest that the centrifugal impact of magic angle spinning alters the lipid's structure in very tight spaces. Additional evidence of phospholipid membranes came from the choline-γ resonance at 3.2 ppm in fresh samples, which disappears with magic angle spinning. Thus, the fatty acid signals are at least partially from membrane bilayer structures, and we propose that they are linked to the submicroscopic vascularization channels similar to the dense canaliculi network in mammalian bones. Our detection of phospholipids from bones depended critically on two factors: (1) the elimination of the overwhelming triglyceride signals from marrows and (2) the preservation of water that biomembranes require. The relaxation data reveal aspects of lipid fluidity that have not been elucidated by previous order parameter studies on model membranes. Relaxation times have long been considered difficult to interpret. A robust and renewed understanding may be beneficial.
Collapse
Affiliation(s)
- Hsin Wang
- Department of Chemistry and Biochemistry, The City College of New York and CUNY Institute for Macromolecular Assemblies, 85 St. Nicholas Terrace, New York, New York 10031, United States
| | - Steve Falcoz
- Department of Physical Therapy, The College of Staten Island, 2800 Victory Blvd, Staten Island, New York 10314, United States
| | - Jean-Philippe Berteau
- Department of Physical Therapy, The College of Staten Island, 2800 Victory Blvd, Staten Island, New York 10314, United States.,New York Centre for Biomedical Engineering, City University of New York - City College of New York, New York, New York 10031, United States.,Nanosciences Initiative, City University of New York - Advance Science Research Center, New York, New York 10031, United States
| |
Collapse
|
3
|
Viani A, Mácová P, Machová D, Mali G. Technical Note: Post-burial alteration of bones: Quantitative characterization with solid-state 1H MAS NMR. Forensic Sci Int 2021; 323:110783. [PMID: 33878550 DOI: 10.1016/j.forsciint.2021.110783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 01/28/2021] [Accepted: 04/05/2021] [Indexed: 12/01/2022]
Abstract
The identification of markers of the modifications occurring in human bones after death and of the sedimentary and post-sedimentary processes affecting their state of preservation, is of interest for several scientific disciplines. A new index, obtained from spectral deconvolution of the 1H MAS NMR spectra of bones, relating the number of organic protons to the amount of hydrogen nuclei in the OH- groups of bioapatite, is proposed as indicator of the state of preservation of the organic fraction. In the osteological material from three different archaeological sites, this index resulted positively correlated with the extent of collagen loss derived from infrared spectroscopy. Its sensitivity to changes in the physical and chemical characteristics of bone allows to identify distinct diagenetic pathways specific to each site and to distinguish different trajectories within the same site.
Collapse
Affiliation(s)
- Alberto Viani
- Institute of Theoretical and Applied Mechanics of the Czech Academy of Sciences, Centre Telč, Prosecká 809/76, 190 00 Praha 9, Czech Republic.
| | - Petra Mácová
- Institute of Theoretical and Applied Mechanics of the Czech Academy of Sciences, Centre Telč, Prosecká 809/76, 190 00 Praha 9, Czech Republic
| | - Dita Machová
- Institute of Theoretical and Applied Mechanics of the Czech Academy of Sciences, Centre Telč, Prosecká 809/76, 190 00 Praha 9, Czech Republic
| | - Gregor Mali
- National Institute of Chemistry, Hajdrihova 19, SI-1001 Ljubljana, Slovenia
| |
Collapse
|
4
|
Coppel Y, Prigent Y, Grégoire G. Characterization of hydrogenated dentin components by advanced 1H solid-state NMR experiments. Acta Biomater 2021; 120:156-166. [PMID: 32860946 DOI: 10.1016/j.actbio.2020.08.022] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Revised: 07/30/2020] [Accepted: 08/15/2020] [Indexed: 12/20/2022]
Abstract
Collecting information about molecular organisation on biological materials such as bone and dentin represents a major challenge in attaining a better understanding of their mechanical properties. To that end, solid state Nuclear Magnetic Resonance (ssNMR) spectroscopic study is an appropriate strategy to provide atomic structural details on these amorphous composite materials. However, species like water molecules and hydroxyl groups are usually observed through 1H magic angle spinning (MAS) ssNMR that suffers from poor resolution due to strong signal overlapping, making their identification difficult. This paper proposes a set of ssNMR experiments for 1H characterization of the main components of human dentin, based on homo- and hetero-nuclear dipolar couplings and composed mostly of fast 1D experiments. The 1H assignment is assisted by straightforward sample modifications: vacuum drying, deuterium exchange and demineralization. These experiments allow the hydrogen signal edition of dentin species like water molecules, HPO42- and OH- groups, depending on their localization (bound to the organic phase, linked to apatite or at the interface) and their dynamic behaviour. This ssNMR toolbox has the potential to provide important structural and dynamic information on chemical and physical modifications of biomaterials. STATEMENT OF SIGNIFICANCE: Molecular characterisation of apatitic biomaterials by biophysical techniques is extremely difficult due to their complex and amorphous nature. It is, however, crucial to obtain such information if we want to understand their mechanical properties in relation to their physical state, for example their hydration levels. In this article we used a set of solid state NMR experiments and sample modifications to distinguish 1H signal of human dentin components with a particular attention to water molecules, known for their major role in biomaterial structuring.
Collapse
Affiliation(s)
- Yannick Coppel
- Laboratoire de Chimie de Coordination UPR8241, CNRS, 205 Rte de Narbonne, F-31077, Toulouse Cedex 04, France.
| | - Yann Prigent
- Institut de Chimie de Toulouse (ICT) - FR 2599, Faculté des Sciences et de l'Ingénierie, Université Toulouse III, 31062 Toulouse, France
| | - Geneviève Grégoire
- Faculté d'Odontologie, Toulouse Cedex 31062; Unité de Recherche Biomatériaux Innovants et Interfaces EA4462/URB2i, Université Paris, 92120, France
| |
Collapse
|
5
|
Wu VM, Ahmed MK, Mostafa MS, Uskoković V. Empirical and theoretical insights into the structural effects of selenite doping in hydroxyapatite and the ensuing inhibition of osteoclasts. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2020; 117:111257. [PMID: 32919627 PMCID: PMC7501993 DOI: 10.1016/j.msec.2020.111257] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 04/02/2020] [Accepted: 06/30/2020] [Indexed: 12/14/2022]
Abstract
The use of ions as therapeutic agents has the potential to minimize the use of small-molecule drugs and biologics for the same purpose, thus providing a potentially more economic and less adverse means of treating, ameliorating or preventing a number of diseases. Hydroxyapatite (HAp) is a solid compound capable of accommodating foreign ions with a broad range of sizes and charges and its properties can dramatically change with the incorporation of these ionic additives. While most ionic substitutes in HAp have been monatomic cations, their lesser atomic weight, higher diffusivity, chaotropy and a lesser residence time on surfaces theoretically makes them prone to exert a lesser influence on the material/cell interaction than the more kosmotropic oxyanions. Selenite ion as an anionic substitution in HAp was explored in this study for its ability to affect the short-range and the long-range crystalline symmetry and solubility as well as for its ability to affect the osteoclast activity. We combined microstructural, crystallographic and spectroscopic analyses with quantum mechanical calculations to understand the structural effects of doping HAp with selenite. Integration of selenite ions into the crystal structure of HAp elongated the crystals along the c-axis, but isotropically lowered the crystallinity. It also increased the roughness of the material in direct proportion with the content of the selenite dopant, thus having a potentially positive effect on cell adhesion and integration with the host tissue. Selenite in total acted as a crystal structure breaker, but was also able to bring about symmetry at the local and global scales within specific concentration windows, indicating a variety of often mutually antagonistic crystallographic effects that it can induce in a concentration-dependent manner. Experimental determination of the lattice strain coupled with ab initio calculations on three different forms of carbonated HAp (A-type, B-type, AB-type) demonstrated that selenite ions initially substitute carbonates in the crystal structure of carbonated HAp, before substituting phosphates at higher concentrations. The most energetically favored selenite-doped HAp is of AB-type, followed by the B-type and only then by the A-type. This order of stability was entailed by the variation in the geometry and orientation of both the selenite ion and its neighboring phosphates and/or carbonates. The incorporation of selenite in different types of carbonated HAp also caused variations of different thermodynamic parameters, including entropy, enthalpy, heat capacity, and the Gibbs free energy. Solubility of HAp accommodating 1.2 wt% of selenite was 2.5 times higher than that of undoped HAp and the ensuing release of the selenite ion was directly responsible for inhibiting RAW264.7 osteoclasts. Dose-response curves demonstrated that the inhibition of osteoclasts was directly proportional to the concentration of selenite-doped HAp and to the selenite content in it. Meanwhile, selenite-doped HAp had a significantly less adverse effect on osteoblastic K7M2 and MC3T3-E1 cells than on RAW264.7 osteoclasts. The therapeutically promising osteoblast vs. osteoclast selectivity of inhibition was absent when the cells were challenged with undoped HAp, indicating that it is caused by selenite ions in HAp rather than by HAp alone. It is concluded that like three oxygens building the selenite pyramid, the coupling of (1) experimental materials science, (2) quantum mechanical modeling and (3) biological assaying is a triad from which a deeper understanding of ion-doped HAp and other biomaterials can emanate.
Collapse
Affiliation(s)
| | - M K Ahmed
- Department of Physics, Faculty of Science, Suez University, Suez, Egypt
| | - Mervat S Mostafa
- Science and Technology Center of Excellence, Ministry of Military Production, Cairo, Egypt
| | - Vuk Uskoković
- Tardigrade Nano, 7 Park Vista, Irvine, CA 92604, USA; Department of Mechanical and Aerospace Engineering, University of California, Irvine, Engineering Gateway 4200, Irvine, CA 92697, USA.
| |
Collapse
|
6
|
Zhang Z, Oss A, Org ML, Samoson A, Li M, Tan H, Su Y, Yang J. Selectively Enhanced 1H- 1H Correlations in Proton-Detected Solid-State NMR under Ultrafast MAS Conditions. J Phys Chem Lett 2020; 11:8077-8083. [PMID: 32880459 DOI: 10.1021/acs.jpclett.0c02412] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Proton-detected solid-state NMR has emerged as a powerful analytical technique in structural elucidation via 1H-1H correlations, which are mostly established by broadband methods. We propose a new class of frequency-selective homonuclear recoupling methods to selectively enhance 1H-1H correlations of interest under ultrafast magic-angle spinning (MAS). These methods, dubbed as selective phase-optimized recoupling (SPR), can provide a sensitivity enhancement by a factor of ∼3 over the widely used radio-frequency-driven recoupling (RFDR) to observe 1HN-1HN contacts in a protonated tripeptide N-formyl-Met-Leu-Phe (fMLF) under 150 kHz MAS and are successfully utilized to probe a long-range 1H-1H contact in a pharmaceutical molecule, the hydrochloride form of pioglitazone (PIO-HCl). SPR is not only highly efficient in frequency-selective recoupling but also easy to implement, imparting to it great potential to probe 1H-1H contacts for the structural elucidation of organic solids such as proteins and pharmaceuticals under ultrafast MAS conditions.
Collapse
Affiliation(s)
- Zhengfeng Zhang
- National Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, P. R. China
| | - Andres Oss
- Tallinn University of Technology, Tallinn 19086, Estonia
| | - Mai-Liis Org
- Tallinn University of Technology, Tallinn 19086, Estonia
| | - Ago Samoson
- Tallinn University of Technology, Tallinn 19086, Estonia
| | - Mingyue Li
- Pharmaceutical Sciences, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Huan Tan
- National Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Yongchao Su
- Pharmaceutical Sciences, Merck & Co., Inc., Kenilworth, New Jersey 07033, United States
| | - Jun Yang
- National Center for Magnetic Resonance in Wuhan, Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan 430071, P. R. China
- Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, P. R. China
| |
Collapse
|
7
|
Gervais C, Bonhomme C, Laurencin D. Recent directions in the solid-state NMR study of synthetic and natural calcium phosphates. SOLID STATE NUCLEAR MAGNETIC RESONANCE 2020; 107:101663. [PMID: 32325374 DOI: 10.1016/j.ssnmr.2020.101663] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Revised: 03/29/2020] [Accepted: 04/02/2020] [Indexed: 06/11/2023]
Abstract
Materials containing a calcium phosphate component have been the subject of much interest to NMR spectroscopists, especially in view of understanding the structure and properties of mineralized tissues like bone and teeth, and of developing synthetic biomaterials for bone regeneration. Here, we present a selection of recent developments in their structural characterization using advanced solid state NMR experiments, highlighting the level of insight which can now be accessed.
Collapse
Affiliation(s)
- Christel Gervais
- Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), UMR 7574, Sorbonne Université, CNRS, 75005, Paris, France
| | - Christian Bonhomme
- Laboratoire de Chimie de la Matière Condensée de Paris (LCMCP), UMR 7574, Sorbonne Université, CNRS, 75005, Paris, France
| | | |
Collapse
|